[QUICK UPDATE]

Got up to 300 round of 7.62x39 through the rifle with the Plum Crazy lower on it. Everything still looks/feel new. Should be able to get up to 500+ rounds through by the end of next week.

[/UPDATE]

I'm posting this up here to try an consolidate some of the posts I put in another thread (that also strayed quite a bit off topic as well)

I just got two lowers in. They were complete, LPK installed with buffer/tube/spring and 6-position stock (commercial tube). I bought them for $99/each, which was a hard price to pass up to try them out!

First impressions;

Nicer then I expected, actually. The molding is nice, no real noticeable burrs/blemishes. I was surprised that EVERYTHING is polymer. I kind of expected the take-down pins to be metal at least. Nope. Not including the stock, the only metal I can see are the trigger springs. I'd be lying is I didn't admit that everything being polymer does nag a bit in the back of my mind, in terms of how well everything will hold up long-term. As it sits right now though everything fits well and it nice and tight.

I attached two different uppers to each lower to inspect the fit. Each upper snapped on easily, and had a tight fit, but not too much that made it a PITA to swap them out. One upper is an ASA 16" M4-style chambered in 5.56, the other is a Model1 16" chambered in 7.62x39.

One thing I noticed right away was the weight, or lack of. These lowers are LIGHT, and it's very easy to feel the difference.

All of the metal mags I tested dropped free from the mag well very easily. However, both the PMAG and Lancer L5 magazines needed a tap or shake to get them to drop. They just had a little bit of a drag to them. I'll be curious to see if they "wear in" at all.

The trigger has a very crisp feel. The reset is quick, and there is little to no creep. Again, I'll be curious to see if it stays that way after everything wears in.

Here are a couple pics with the ASA upper on the Plum Crazy polymer lower;





With the 7.62x39 upper;

(I moved my Ergo grip and ACS stock over to the lower)





Weight

Essential Arms aluminum lower with standard parts kit installed (no stock/buffer tube) - 1 pound 0.3 ounces (16.3 ounces)

Plum Crazy polymer lower with polymer parts kit installed (no stock/buffer tube) - 8.8 ounces

Weight savings of just about a half pound (7.5 ounces)...not bad, especially if you want to put together a real light-weight rifle.

First trip to the range;

Fired 180 rounds of 5.56 and 150 rounds of 7.62x39. The lowers ran great. No problems. The trigger is heavy, but crisp, virtually no creep and the reset is quick. I was surprised that this lower worked 100% with my 7.62x39 upper, as I needed to install a heavier spring in the original lower to deal with the notoriously hard primers, the springs in these are heavy enough as they sit.

The 7.62x39 felt like it had a bit more recoil, possibly due to lack of weight or the lighter buffer the stock had in it. I just swapped everything from the original lower (ACS stock with tube/spring/buffer, Ergo grip) over to the polymer lower and will try to get back out to the range this week to see how it feels. The 5.56 rifle felt lighter in-hand, but I didn't feel any more recoil, but the 5.56 round is pretty soft as it is. I didn't notice the 7.62x39 as being too much lighter, probably because it has a fairly heavy setup (M.I. rails, 1-4x scope/mount, heavy barrel) compared to the 5.56 setup (Magpul handguards, EOTech, M4 barrel).

I loaded the magazines light, only 5-10 rounds, each time to work everything as much as I could with the short time I had. The mag release and safety switch showed no signs of any wear, the trigger is just as tight. Everything looks good. The only thing I noticed that I thought was odd, was that I could set the safety ON when the hammer was not charged. I can't do this on any of my other lowers. Just had to remember that if/when I saw the safety on it didn't mean that the rifle was charged.

Post range trip inspection

No pin-walking of any kind. Everything looks/feels just as tight as it did initially.

One of the hammers showed some wear on the edges where the carrier passed over it, the other still looks brand-new. After looking at the bolt-carriers it turns out one (7.62x39, left) has a shielded firing-pin while the other does not (5.56, right). Here's a pic;



I'm going to take out the hammer and radius the edges to relieve the area getting "cut"

Conclusion so far

Still pretty impressed with the lowers overall. For the $$ they are, at this point, a steal. We'll see how they fair with some use. I'm leaving this lower as the full-time lower on the 7.62x39 gun. That one should show signs of wear before the 5.56 model. I've got a couple more range trips coming up so when I hit the 500 and 1000 round marks I'll update this post and any new information.

Yeah I'm not a big fan of polymer lower . So even the lower parts are polymer ? Not sure i would like that. What about the pins are those plastic too? They don't look too beefy where the back take down pin is. Looks like you could put an auto sear in there. Not a DIAS. i'm talking an Auto sear like an M16 has. Looks like that matrial that an AR15 lower would have there to prevent someone from just drilling the holes and putting it in there isn't there.

Regardless of how I feel about these, your range trip photos / writeup / review were done very well... Great job.

X 2... Could you put a regular LPK on the polymer lower?

Awesome!!! What foregrip is that?

Tango Down stubby, one is a standard mount, while the other is the quick-detach version. If you were looking to get one, get the QD, the standard one can be a PITA to take off/on

I've one of these lowers on a 14.5" carbine (ASA Barrel, Vltor cas-v AZ AR FTW!!) but with a DPMS LPK. I've put several hundred rounds through it and have had 0 problems so far.

Just about every weapon I own is covered in polymer parts and the lower is a relatively low stress part.

No reason to destroy good parts.

Tag !

It would be a fine plinker for the kids but not for LE use.

You guys DO realize that it's not unusual in this day and age to have polymer internals, including the hammer. Anyone have an MSAR STG-556 or E4?

tag